<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>使用grid</title>
    <style>
        .container {
            display: grid;
            grid-template-columns: 300px auto 300px;
            grid-template-rows: 400px;

        }

        .left {

            background-color: red;

        }

        .right {

            background-color: blue;

        }

        .center {

            background-color: yellow;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="left"></div>
        <div class="center"></div>
        <div class="right"></div>
    </div>
</body>

</html>